Which of the following civilizations had the biggest impact on Russian history?
Romans

The traditional start-date of specifically Russian history is the establishment of the Rus' state in the north in 862 ruled by Vikings. Staraya Ladoga and Novgorod became the first major cities of the new union of immigrants from Scandinavia with the Slavs and Finno-Ugrians.

federal power is further limited with a system of checks and balances that gives each branch of government a measure of power over the others.

explanation:

increase in population